State officials are urging Georgia school superintendents to consider adopting a daily 30-minute period of physical activity for elementary school students.

A letter sent this week by state school Superintendent John Barge and by Dr. Brenda Fitzgerald, commissioner of the state Department of Public Health, cites the obesity epidemic as the impetus for the voluntary “Power Up for 30” program.

“We must get our students moving more during the school day,’’ their letter says. “Physical activity means higher test scores, increased attention in class and a healthier student population. To make this possible, we need your help.”

The letter encourages schools to include the 30 minutes of physical activity in addition to regular PE classes.

Georgia has the second-highest childhood obesity rate in the nation, state officials say.

Barge and Fitzgerald also cite the weak performance by many students in the Georgia SHAPE program’s fitness assessment. Only 16 percent of Georgia students passed all five fitness tests, and 20 percent were unable to pass any of the FitnessGram tests.

“We looked at the data and [saw] a need to provide kids more opportunities to get moving,’’ Therese McGuire, health and physical education specialist with the state Department of Education, told GHN on Thursday. “We’d like to move the results of the FitnessGram in a positive direction.’’

The number of schools already providing extra physical activity is “definitely a minority,’’ she said.

The 30 minutes of exercise has long been championed by Fitzgerald. “Childhood obesity is the No. 1 [health] issue in our state,’’ she said recently to a gathering at the Capitol.

The letter to superintendents adds that some schools are using heart rate measurements and physical activity to demonstrate math and science concepts during classes.

“Everybody wants students to be healthier,’’ McGuire said. “Healthier students do better academically.’’

McGuire said her agency and Public Health would offer ideas on how to implement the 30-minute program, including the creation of running clubs. The target for startup is this fall, she said. The program would be voluntary for both schools and students.

There are no plans at this time for a similar program for middle school or high school students, she added.

Several initiatives are under way to reduce the childhood obesity problem, including Gov. Nathan Deal’s SHAPE program, a public-private partnership launched last year. Many schools across the state are improving their cafeteria food, emphasizing nutrition over excess calories.

Other states are promoting physical activity for students. North Carolina, for example, requires schools to provide a minimum of 30 minutes of daily moderate-to-vigorous physical activity to all students in grades K to 8.

Mississippi enacted legislation in 2007 that requires 150 minutes per week of physical activity-based instruction and 45 minutes per week of health education for grades K to 8.